Temperature control switch



1943- J. P. BULLER TEMPERATURE CONTROL SWITCH 2 Sheets-Sheet 1 Filed March 28 1940 Inventor Aiforr y Aug. 17, 1943. J. P. BULLER TEMPERATURE CONTROL SWITCH 2 Sheets-Sheet 2 Filed March 28, 1940 n, 111 11 E: ctcccc 04 0.11! NNMM3322 1 Attorney Patented Aug. 17, 1943 UNITED STATES, PATENT OFFICE 2,327,014 TEMPERATURE ooN'mor. swrron mm 2. Bullet, Rlnnvood, Okla. Application March 28, 1940, Serial No. 326,512

2 Claims- (01; 200-138) My invention relates to improvements in selective automatic thermostatic controis for elec tric refrigerators, and the primary object of the invention is to provide an arrangement of this character whereby the temperature within the refrigerator will remain constant at the selected temperature despite Variation of temperature outside of the refrigerator, and wherein the box temperature is regulated and controlled without requiring turning up the pressure during the day and turning the pressure down during the night.

Other important objects and advantages of my invention will be apparent from a reading of the following description the drawings, wherein I have shown invention In the drawings: a to Figure l a general schematic showing an arrangement in accordance with the present taken in connection with for purposes of illustration 9. preferred embodiment of my invention applied to a conventional electrical reirigerator,

Figure is ac. enlarged front elevatioual view of the meclwnioal type of thermometer switch with attendant electrical connections and the sliding temperature selecting switch Fimre 3 a fragmep ary transverse vertical sectional vi Figme approxitcward the left the euro tioli oi the orrow.

Figure is afiragme 51 top View of the sliding selective Figure 5 is a fragmc tary view enotl er thermometer control s J. a v31 arrange ent winch.

can be Sill i ed for shown m Figure 2 of the drawi gs, I

Referring in detail to drawin the nu meral it generally designates a conventional type of electrical refrigerator which includes within its interior the refrigerating uriit l which accordance with the present invention has mounted in a suitably Visible place thereon the thermometer switch which is generally designated 8 from which lead respective conduits 9 and it enclosing conductors leading to opposite sides of the current supply i I. If desired a reducing transformer 12 may be inserted in one side of the circuit, preferably in the wire iii in the conduit to. The conduit 9 contains the wire II which leads to the opposite side of the supply circuit and has connected therein the sliding selector switch which is generally designated Ii.

The sliding switch 15 comprises a preferably slider positioned in alignment with the numerals it,

and for selectively bridging these contacts it there is provided the O-shaped slider 2! whose laterally inwardly turned flanges 22 engage conforming vertical slots 23 in the opposite sides of the body l6 as clearly shown in Figure with the right angle flange adjacent the plate I! engaging the contacts 26. The slider of suillcient length so that when pushed to extreme depressed position it will engage bridge all of the contacts at. The body portion 86 is suiilciently vertically elongated so the ill can slide upwardly e. smilcient die to engage only the uppermost of the co a 2 The current supply wire is, is come the slider 2| a indicated in Figure 1, wk wires H, of which one leads from each 0- contacts 20, are contained in the conduit 9 c lead to corresponding contacts 24 which are ranged in an arcuately series on a electric block 25 mounted on a partition tending across the cylih a1 casing of the i mometer switch 8, wii i the rear part of the said c its individual wires it openings 27 in the part pointer 28 is fixed to are to extend in fro the serie as indicated in its e 3 and easement with any one accordance with heated to the as mechanism 39 behind anism so being of sui A suitable glass it is mounted in rent o pointer and secured in the casing so as em the position of pointer 28 to view while door 32 of the refrigerator 5 is in an open pom tion.

Referring now to the form of thermometer switch illustrated in Figure 5 of the drawings which may be substituted optionally for that shown in Figure 2, there is involved a glass or other suitable material thermometer tube em through which the mercury 28a may be seen as it rises and falls due to temperature change. At one side of the thermometer tube is mounted a plate Ila having temperature degree designa- 2 ations I80 thereon and at the opposite side of the thermometer tube and exposed within the bore thereof are vertically spaced contacts 20a corresponding in position to the designations Ma. The wires it which lead to the slider equipped selector switch it are connected to the contacts 26a similar to the contacts 20 of the first described embodiment. It is obvious that as the mercury 28a rises and falls within the thermometer tube sla that the various contacts 29a below the uppermost reach of the mercury will be bridged by the mercury. In the case of the last described embodiment the connections of the wires it with the contacts 26 will be exactly the reverse of the connection of the contacts Zil with the contacts 26, because of the inverted relationship of the progress of the elements which bridge the contacts Eta and 2e, respectively.

In the case of thefirst described embodiment the wire Hi is the wire which completes the circuit between the control of the present invention and the refrigerator unit i, while in the case of the second described embodiment the wire I lb connected to the mercury 28 below the contacts 28a is the wire which carries the current from the line to the control.

Each contact point fore, when the air within the refrigerator com-.

partment reaches the temperature set on the switch is and the pointer 28 on the thermometer switch 8 is thereby caused to engage the conesponding one of its contacts 25, the current sup- 26 of the thermometer switch 8 corresponds to a-certain degree of temconnected to the electrode of the mercury bulb, so that the current will flow through the mercury. switch and the slide switch tothe motor.

Although I- have shown and described herein preferred embodiments of my invention, it is to be definitely understood that I do not wish to limit the invention to the precise forms and arrangements shown and described, except as may be required by the scope of the subjoined claims.

Having described the invention, what is claimed as new is:

1. A switch in an electric circuit comprising a non-conductive, elongated, stationary body and a conductive selector member slidably mounted tin "son; said body being L-shaped and provided on both opposite flat sides with longitudinal slots and on one of said sides with a flat lateral plate, a series of longitudinally spaced contact points on said body adjacent said flat plate having a corresponding graduation, said selector member being U-shaped and having inwardly projecting flanges engaging in said slots and bearing against said contact points, the' selector member being longitudinally adjustable along said body to selectively engage one or all of said contact points, and a conductive pointer adapted for marking the temperature produced, a thermoresponsive mechanism adapted for positioning said pointer, a series of spaced, arcuately arranged contact points in a dielectric block with corresponding graduation making for cooperating with said pointer, individual leads connecting corresponding contact points on said body with the contact points in said arcuate block; a conductor between said selector member and one pole in the electric circuit and another conductor from said pointer to the other poleof said circuit.

2. A switch in an electric circuit comprising a non-conductive, elongated, stationary body and a conductive selector member slidably mounted thereon; said body being L-shaped and provided on both opposite fiat sides with longitudinal slots ply goes through the two switches to the compressor motor so as to operate the compressor until the temperature in the refrigerator compartment is lowered sufliciently to permit the pointer 28 to move off the described contact and thereby break the motor circuit.

The same essential actions take place in an installation wherein the mercury type thermometer switch 8a is used in place of the pointer switch 8.

It will be observed that it is characteristic of the construction of the slide switch 15 that all of its contact points 2!! above that corresponding to that of the set temperature are contacted by the slide. This arrangement is provided so that the operation of the compressor for the described reduction of box temperature will take place and continue even though that temperature should temporarily g0 substantially above the temperature for which the slide switch has been set, thereby assuring the necessary reduc tion in temperature.

When using the pointer thermometer switch 3 the lead to the compressor motor should be divided and one terminal connected to the slider 2! of the slide switch i5 and the other terminal to the pointer 28. When using the mercury type thermometer switch 8a, the motor lead should be similarly cut and one terminal connected to slider 2| of the slide switch l5 and the other terminal and on one of said sides with a fiat lateral plate, a series of longitudinally spaced contact points on said body adjacent said fiat plate having a corresponding graduation, said selector member being U-shaped and having inwardly projecting flanges engaging in said slots and bearing against said contact points, the selector member being longitudinally adjustable along said-body to selectively engage one or all of said contact points, and a conductive pointer adapted for marking the temperature produced, a thermoresponsive mechanism adapted for positioning said pointer, a series of spaced, arcuately arranged contact points in a dielectric block with corresponding graduation marking for cooperating with said pointer, individual leads connecting corresponding contact points on said body with the contact points in said arcuate block, a conductor between said selector member and one pole in the electric circuit and another conductor from said pointer to the other pole of said circuit, said selector member being suificiently long to engage all of the contact points in one extreme position and said body being sufliciently long to enable said selector member to be selectively adjusted on said body to the opposite extreme position or any intermediate position in which said selector member engages only the adjacent end contact point of said series of contact points.

JOHNP. BULLER. 

